Which stock IROC would be quicker a 1985 LB9 G92 with the 3.42 or the 1988 L98 G92 with 3.27 gears?

 

L98

 

There's no replacement for displacement!

L98

I wouldn't be surprised to see the car with 3.42's get off the line quicker than a L98 with 2.73's (not 3.27 ... the L98 w/ 3.27 would win off the line). But the L98 will win in the 1/8 or the 1/4 every time ... stock to stock.

Also, since you said "quicker", I assume you're talking about drag racing, and I am obligated to reply that it depends on the driver.

 

L98 , the LB9 might be as quick if the L98 had the 2.77 rear gear.

 

I found an old popular hot rodding with a road test of a 1985 LB9 with 3.42 and it ran 14.7 and 6.9 0-60 times. I was just wondering what the 350 times were. seems with the gear difference the times would be about the same.

 

It seems there is a wide range of 1/4 mile times out of the 350 times , I know that my 89 L98 iroc that was loaded with all options but t/tops run a 13.89 at 99 in the 1/4 with small bolt ons ( no cats , cat back exhaust , air foil , and air box cut out with k&n filters). That has been the fastest of the 4 irocs I have owned. It ran 8.86 @ 78 in the 1/8 mile , and I had a stripped down 90 iroc with the L98 and only option was a/c ( it only had a am/fm radio and roll up windows) and it ran 8.93 in the 1/8 @ 77 but I never got to run that car in the 1/4.

 

Thats what us thirdgen owners are supposed to say to 4 bangers? haha

 

No, that's what we're supposed to say to the mustang 5.0 guys.

 

In my opinion they are almost too close to call. Like Ls2 GTO, my 89 GTA (loaded including t-tops) with similar mods went 13.70 at 99mph - but bone stock it went 14.66 at almost 92mph. I also know of a stock LB9 5-speed car with 3.08 gears that runs 14.89 at 91mph. Lately I've been picking up mags from the late 80's and have noticed similar results from their tests, not the same times but how close the L98 and LB9 cars were (at least the 5 speed cars)

 

those years will give the win to the L98
if the 5spd car was a 90-92 i would say the L98 would be in trouble since the 88 had a terrible mistake for a camshaft.87,89-92 were hot and could run real good!


manual tranny makes a huge difference!

 

A L98 with an auto is about the same as the LB9/M5 with the 3.42 or 3.45 gear. It ultimately depends on the driver of the LB9 car, But it is much easier for a L98 car to win, less driver variable.

My 87 LB9/M5 car was pretty quick, of course its been 8 years since I drove it.

John
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From 1990 - 1992 All TPI cars got the same cam, as they did not get the peanut cam according to the information I have. BUT the 1988 & 1989 L98 cam was actually hotter than the 90+ cam... I think the problem with some of the LB9/M5 cars in 1988 & 1988 would have been the rear axle as the LB9 with the M5 was not standard with the 3.42/3.45 gears, The 308 was an option. Which would make a huge difference.

John

 

There's not enough difference between 3.42 and 3.27 to make up for the difference in HP. As I stated earlier, though, I think a L98 with 2.73 (10-bolt) or 2.77 (9-bolt) would get a run for its money from a LB9 w/ 3.42. That's why I made sure to dump my 2.73 when I put my 355 in. The only thing a 2.73 is good for is highway use, or if you have an extremely high HP motor, I hear a tall gear will help you hook better.

 

I found this site http://www.cobranet.com/roadtest.htm it has a lot of road tests 1985 Chevrolet Camaro IROC Z28 305 AOD 3.42 215@4400 275@3200 7.0 15.2@91mph 1987 Chevrolet Camaro IROC Z28 350 AOD 3.27 230@4000 330@3200 6.6 15.23@91.2mph 1988 Chevrolet Camaro IROC Z28 350 AOD 3.27 235@4200 335@3400 7.2 15.67@91.6mph 1989 Chevrolet Camaro IROC Z28 350 AOD 3.27 230@4000 330@3200 6.9 15.54@91.7mph Looks to be pretty close.

 

I've got a Magazine article from Motor Trend. Good old pony car shootout from 1988. Iroc with a L98 and auto, Formula with LB9 and five speed and a Mustang GT. The numbers were 6.95 for the Iroc, 7.5 for the Formula and 7.23 for the Stang. in the quarter they were 15.54/91.7 for the Iroc, 15.95/88.5 for the Formula and 15.77/92.8 for the Stang. Now while the Mustang was able to run with the F-bodies in the acceleration tests it was slaughtered on the handling tests with both F-bodies getting .89 to the stang .8 on the skidpad, the Formula had the best slalom speed at 61.9 Iroc was 59.6 with the stang in the middle. Also when it comes to the road course the f bodies were only .38 seconds apart with the Iroc leading the way again slaughtering the Mustang. The Iroc had a 2.73 ratio as did the Mustang. The Formula had a 3.08 ratio. Ironically the Iroc generated almost equal numbers to a 15th anniversary Trans Am with a 305 HO and a 5 speed but that car had a 3.73 gear set. In some cases the 305 HO was quicker. I mention this only to show what gear ratios can do. I will also mention that I will be sending this article to JT for posting soon.

 

at the end of the 1/4, the L98 would most likely have it.

Off the line ... depends. In 86, the 700R4 had the high stall (1950) and it was faster off the line than the later l98 cars which had the 1750 stall (shift points in 86 were also in the 52-5400 range, and in later years it was brought down to 4800 or so). I don't recall what the 85 had for stall in the torque convertor.

Considering the variations from year to year ... off the line will depend on many things (driver included). But at the top of the 1/4 mile, the L98 should pull ahead.

Mark.

 

It would depend on driver skill in the LB9 because cars are almost a dead heat.

 

An L98 G92 IROC-Z, Z28, or Formula are the fastest V8 factory Third Gens. The LB9 T-5 G92's aren't that far behind, but they still are.

 

Just to throw even more numbers at this, my 88 Formula 350 (3.27 gear) ran 14.7 consistantly in 2006 as a bone stock car. An 89 IROC LB9 5spd G92 that i go to the track with often consistantly ran 14.8 as a bone stock car also in 2006. Both cars had roughly 50K orig. miles on them.

As with what the majority is saying, the driver is the ultimate factor but at that time this was all those cars could do in stock form. However I ran my car in stock form for the first year I owned it and noticed air qaulity is a huge factor in the times I was running. My L98 ran 14.7 at the quickest and 15.3 at the slowest that season. To get the 14.7's out of it, the air would have to be less than 80 degrees out with low humidity and I would push the car through the staging lanes only letting the engine heat to about 120-130 degrees at the time of each pass.

(again the cars were BONE stock, no adjusted timing, no descreened MAF's, nothing! I dropped .4 when I did those two "free" mods 14.3 consistantly )

 

What 2 "free" mods? i wanna drop .4 on my et.

 

There i meant advanced timing and a descreened MAF. There some more "free" mods just use search to find them.

 

Yah, but they're more fun to drive!

If time and $ allowed someday, I would like to prep both my Formula and GTA per the Pure Stock Drag (NHRA engine) rules and see how fast each can really go in maxed-out stock trim. I'm pretty sure that they would be no where near the slowest 305 and 350 inch entries compared to the 1955 to 1974 cars that are legal for the race.

 

It is actually interesting that the GTO's and the other Muscle cars of the 50's, 60's and early 70's were not as fast as people want to believe. Only the few cars that were specially built were really fast, like the COPO cars and the really rare ZL1's Most of the "Muscle" cars from the 60's were still in the 14's and 15's... just like later 3rd gens...

The cool thing is you can take a Z28, or a WS6 3rd gen in stock form to a road course and just about stomp anything out there from the earlier era that is in stock trim...

John

 

An L98 G92 Third Gen is faster than about 75-80% or more of 60's-70's muscle. That number could be higher, but the lousy tires did hold alot of those cars back, not by that much though. Not only that, Third handling is light years better, (still stands up to todays cars) the same goes for the braking, aerodynamics, build quality, on and on. Alot of people just have no clue. Cars that ran better than low 14's were very few and mostly rare/expensive then. That was really fast for the times though. Today's modern musclecars absolutley destroy nearly all of them, as people are gonna see once again when the 5th Gen hits the streets in about 2 months.

 

Some of the older cars were really fast:

Any of the 400 pontiac Firebirds of the 60's or very early 70's were fast
Any of the Hemi or 440 cuda's, challengers or chargers were fast
Big Block camaros and Chevelle's were also fast

There were a lot of cars that were fast and could run in the low 14s off the dealership floor. The problem is that most people's memories of these cars are now 30+ years old and nostalgia also playes a part

The thing about a lot of these older cars that made them seem so fast was that they had much worse suspensions, a lot of them had drum or manual brakes that weren't nearly as good as modern brakes, and most of them rode on bias ply tires that were only 6 or 7 inches wide. They also had gobs of torque.

All of this added up to a car that felt like it had almost uncontrollable power, because it didn't have very good control.

I still like the style and variety of the old iron. Most of today's cars are cookie-cutter compared to the 60's and 70's.

I do agree that most of the 'modern' muscle cars are just as fast, and sometimes faster, than the old iron.

 

You are correct, some of those cars did get into the 14's... As did many of the L98 cars... Its an oversight, and I have seen posts with people claiming even in the high 13's with some "Free-Mods" But then it would no longer be "Stock"...

My point is very few if any cars from the 60's got into the 13's off the show room that were not specially made with race trim... Specially made by the factory to meet some mandatory production, special COPO cars etc... Sounds like a 1LE to me...

My 67 Riv is a low 15 Second car, to be honest it feels like a 13 second car. But it is so heavy you can really feel the power. It will put you back into the seat and you cannot touch the dash board before 60Mph... But my 87 Formula is faster in the quarter, it does not feel as fast, but it really is... Old cars probably felt faster because they did not handle as well...

John

 

I hope to be an example of that this September! I'll be a Pure Stock newbie and am therefore not setting the sights too high. My 68 is still in pieces so I can't say with even 99% confidence that I'll make the race... wish me luck.

As far as Third Gens go, I think that a no-option 84 L69 Z28 with the 15" tires would stand about as good a chance as any in making an impressive Pure Stock showing (the Q-Jet could pull all the way down the 1320). Taller/narrower 15" tires with a good dry-traction compound should be easier to hook up than the short-sidewall 245 16"s, no? You can run any R&P you want, so gear-up an auto trans car, NHRA the motor (9.82:1 CR) and razor tune it with all the little tricks. Use synthetic lubes all around, a K&N, install a free-flow exhuast, put a "hot shoe" in the seat and let it fly.

Could it crack the 13s or am I smokin' crack?

The top 6 cars at the 07 PSMCDR (08 was a rain-out) 327ci and under (NA) were as follows:

1) 1957 Corvette - 283/270/4M 13.160 @ 104.4
2) 1966 Corvette - 327/350/4M 13.476 @ 103.8
3) 1968 Z28 - 302/290/4M 13.562 @ 102.5
4) 1957 Ford 300 - 312/300/4M 13.708 @ 105.1
5) 1970 Boss 302 - 302/290/4M 14.456 @ 99.97
6) 1969 Z28 - 302/290/4M 14.932 @ 96.33

Magazine road tests from 1984 would have a showroom floor L69 in practically a dead heat with the 69 Z at number 6! There were nine cars slower than that.

I know a lot of people poo-poo the really fast Pure Stock cars as being anything but stock. However, in the little time I've hovered around that scene I truly believe that these guys are masters at wringing out every little bit of power/torque in a given combo. I would like to see one of the gurus put the mojo on an L69 Z like I outlined above and observe what happens. I've heard rumor that the organizers of the PSMCDR actually respect 3rd Gens and the like, but it would be opening a whole new can of worms by inviting late models to the party. If/when I get to know them better, I'll ask if that is true.